本文主要讲述的是用struts2搭建服务器，从数据库获取数据，客户端通过json解析获得数据的方法。
以下主要为服务器端的代码。
图书实体类：
public class Book {
private int bookId;
private String isbn;
private String title;
private String price;
public int getBookId() {
return bookId;
}
public void setBookId(int bookId) {
this.bookId = bookId;
}
public String getIsbn() {
return isbn;
}
public void setIsbn(String isbn) {
this.isbn = isbn;
}
public String getTitle() {
return title;
}
public void setTitle(String title) {
this.title = title;
}
public String getPrice() {
return price;
}
public void setPrice(String price) {
this.price = price;
}
}
public class BookManageMentActivityAction extends ActionSupport {
List<Book> booksList=new ArrayList<Book>();
BookService bs=new BookServiceImpl();
HttpServletResponse response=ServletActionContext.getResponse();//响应客户端的请求，将数据发回去
Book book;
int bookId;
//设置set\get方法，自动获值
public int getBookId() {
return bookId;
}
public void setBookId(int bookId) {
this.bookId = bookId;
}
public void getBookList() {
JSONArray jsonArray=new JSONArray();
//调用业务逻辑层
booksList=bs.getBookList();
for(int i=0;i<booksList.size();i++) {
book=new Book();
book=booksList.get(i);
JSONObject jsonObject=new JSONObject();
jsonObject.put("bookId", book.getBookId());
jsonObject.put("isbn", book.getIsbn());
jsonObject.put("title", book.getTitle());
jsonObject.put("price", book.getPrice());
//这里的图片是直接放在了/WebContent/fileUpload目录下，没有保存到数据库中
jsonObject.put("bookImage","/fileUpload/book"+i+".png");//书的封面
jsonArray.add(jsonObject);
}
try {
response.setCharacterEncoding("utf-8");
response.getWriter().write(jsonArray.toString());
response.getWriter().flush();
response.getWriter().close();
}catch(Exception e) {
e.printStackTrace();
}
}
public void deleteBook() {
JSONObject jsonObject=new JSONObject();
// deleteBook调用的BookServiceImpl.java中已写好的方法
if(bs.deleteBook(bookId)!=0) {
jsonObject.put("message", "删除成功");
}else {
jsonObject.put("message", "删除不成功");
}
try {
//先以text的格式显示，
response.setContentType("text/json;charset=utf-8");//设置客户端显示内容的方式
response.setCharacterEncoding("utf-8");//网络中传输格式
byte[] bytes=jsonObject.toString().getBytes("utf-8");
response.setContentLength(bytes.length);
response.getOutputStream().write(bytes);//write只能传输byte类型的数据
response.getOutputStream().flush();
response.getOutputStream().close();
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
BookServiceImpl.java中得到图书列表和删除操作的代码如下：
public class BookServiceImpl implements BookService {
DbConnection db=new DbConnection();
ResultSet rs=null;
@Override
public List<Book> getBookList() {
// TODO Auto-generated method stub
List<Book> books=new ArrayList();
String strSql="select top 5 * from book_table";
rs=db.executeQuery(strSql);
try {
while(rs.next()){
Book book=new Book();
book.setBookId(rs.getInt("bookId"));
book.setIsbn(rs.getString("isbn"));
book.setTitle(rs.getString("title"));
book.setPrice(rs.getString("price"));
books.add(book);
}
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return books;
}
@Override
public int deleteBook(int bookId) {
// TODO Auto-generated method stub
int bl=0;
String strSql="delete from book_table where bookId="+bookId;
bl=db.executeUpdate(strSql);
return bl;
}
}
配置struts.xml文件
<action name="getBooks" class="jxnu.edu.cn.x3321.action.BookManageMentActivityAction" method="getBookList">
<result type="json">
<!-- 返回类型一定要设置成json,不设置返回页面 -->
</result>
</action>
<action name="deleteBook" class="jxnu.edu.cn.x3321.action.BookManageMentActivityAction" method="deleteBook">
<result type="json">
<!-- 返回类型一定要设置成json,不设置返回页面 -->
</result>
</action>数据库工具类：
public class DbConnection {
private String driver="com.microsoft.sqlserver.jdbc.SQLServerDriver";
//告诉Java数据库名字为什么什么
private String url="jdbc:sqlserver://localhost:1433;DatabaseName=你的数据库的名字";//协议；库或服务器名称；服务器IP，端口
//定义访问远程url的用户名
private String userName="sa";//sql数据库的用户名
private String passWord="1";//sql密码
private Connection conn=null;
private Statement stmt=null;
private ResultSet rs=null;//存放返回的结果集
public static void main(String arg[]) {
DbConnection dc=new DbConnection();//构造函数加载驱动程序
String sql="insert into book_table values('003','Python','45')";
dc.executeUpdate(sql);
}
public DbConnection() {
/* *（1）加载驱动程序 *构造函数在new时执行 */
try {
Class.forName(driver);//自动注册；需要把驱动的jar包导进来；需处理异常
} catch (ClassNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
//只进行删除、添加、修改
public int executeUpdate(String sql) {
int result=0;//不成功
//（2）创建连接 getConnection(url,userName,passWord)
try {
conn=DriverManager.getConnection(url,userName,passWord);
//(3)创建statement
stmt=conn.createStatement();
//(4)执行sql语句
result=stmt.executeUpdate(sql);
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return result;
}
public ResultSet executeQuery(String sql){
//（2）创建连接 getConnection(url,userName,passWord)
try {
conn=DriverManager.getConnection(url,userName,passWord);
//(3)创建statement
stmt=conn.createStatement();
//(4)执行sql语句
rs=stmt.executeQuery(sql);
} catch (SQLException e) {
e.printStackTrace();
}
return rs;
}
//关闭连接函数
//配置文件连接词帮我们管理
public boolean closeConnection(Connection conn) {
boolean bl=false;//关闭成功
if(conn!=null) {
try {
conn.close();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
bl=true;
}else {
bl=false;
}
return bl;
}
}